The Dwarf Gene

The Dw locus is responsible for the dwarf gene found in the dwarf breeds. A rabbit can be either be normal aka false dwarf, true dwarf, or peanut (lethal). For the purposes of this article, these alleles can be denoted DwDw, Dwdw, or dwdw.

DwDw we can call 'normal'. These rabbits exhibit larger size than true dwarfs. All rabbits that are non-dwarf breeds are normals. A certain percentage of rabbits of dwarf breeds are also 'normals'. Normals are true-breeding.

Dwdw, a heterozygote, is a true dwarf. These rabbits have a smaller size and a 'dwarfy' appearance. These only occur in the dwarf breeds. They are not true-breeding.

dwdw is a lethal, and is called a peanut. These rabbits do not have functional pituitary glands, and as such do not produce enough growth hormone to live. These rabbits are very small and underdeveloped, and always die. They usually die at around 5 days of age, but can last up to several weeks.